Integrated bicycle pedal with self centering and lateral release capabilities

ABSTRACT

A bicycle pedal system which attaches a cyclist&#39;s shoe to a bicycle pedal. The system consists of a cleat attached to the cyclist&#39;s shoe under the ball area of the foot. The cleat has two downward projections. These projections feature arcuate tracts for matingly engaging the cleat to a pedal body. The pedal body is shaped to matingly engage the cleat and contains a tensioned mechanism centered in the back of the pedal body. If a rotating force on the cleat exceeds a predetermined level, a release of the shoe cleat from the pedal body occurs. If such rotating forces do not exceed said predetermined level, the shock or movement will be absorbed and the shoe cleat is returned to the optimum position in the center of the pedal body.

This application is a division of Ser. No. 016,277 filed Feb. 19, 1987,now Pat. No. 4,815,333 issued Mar. 28, 1989, which is related to aco-pending application by the same inventor entitled "Self ContainedBraking System for Bicycle Pedals" filed May 27, 1987, Ser. No. 054,577,now Pat. No. 4,819,504 issued Apr. 11, 1989.

FIELD OF THE INVENTION

This invention relates to bicycle pedals and, in particular, to abicycle pedal which is adapted to matingly engage with a cleat attachedto the shoe of a bicycle rider. The pedal is further adapted todisengage itself from the cleat by a twisting motion of the rider's shoeonce predetermined forces have been exceeded.

BACKGROUND OF THE INVENTION

It is a problem in art to provide a bicycle pedal of high pedalingefficiency. An ideal bicycle pedal would efficiently coact with acyclist's foot with respect to downward forces on the pedal, withrespect to upward forces on the pedal as the cyclist lifts his foot, andwith respect to forward and backward forces exerted on the pedal by thecyclist's foot. The ideal pedal would further be easy to get into andout of. In other words, it would be easy for the cyclist to engage hisfoot with the pedal as well as to controllably disengage his foot fromthe pedal.

Numerous bicycle pedal arrangements are known having varying degrees ofpedaling efficiency. A common pedal arrangement is termed the "quill"pedal. The quill pedal is characterized by a main axle section which isattached to a bicycle crank arm and which contains approximately oneinch extensions from the axle section to which parallel cage plates areattached at the front and rear of the pedal. In order to utilize thequill pedal, the cyclist simply pushes his foot against the platformformed by the parallel cage plates. However, only limited performance isobtained from the quill pedal since the cyclist can only use a pushingmotion of his foot to generate pedal power.

Numerous attempts have been made to increase the performance of thequill pedal. One such modification includes the addition of a toe clipwhich comprises a thin metal or plastic attachment to the front cage ofthe pedal. The toe clip is shaped like the toe of a shoe and itsfunction is to prevent a cyclist's shoe from slipping off the pedalduring a forward pedaling motion. To enhance the performance of thequill pedal even further, the toe clip has been modified to allow aleather strap and buckle arrangement to go around or through both thepedal and the toe clip to encircle the cyclist's foot on the top of thepedal. The main advantage provided by the toe clip and strap is that itnot only enables the cyclist to generate power by pushing his footforward against the pedal platform, but it also allows an upward forceto be exerted by his foot. This increases the cyclist's pedalingefficiency.

In order to improve further upon the pedaling efficiency of the quillpedal, a modification called a "cleat" has been developed. This cleatcomprises a small metal or plastic attachment to the cyclist's shoe. Thecleat is slotted and is adapted to matingly engage a quill section ofthe bicycle pedal. The use of the slotted cleat enhances a cyclist'sability over that provided by toe clips and straps since it permits agreater pedaling efficiency to be obtained.

Although the provision of the above mentioned toe clips, straps, andcleats greatly improves a cyclist's pedaling efficiency, it does so atthe cost of numerous disadvantages. To be used efficiently, the toestrap must be tightened to such a degree that the removal of the foot isoften difficult, if not impossible. Further, the length of the toe strapcan be increased only by the cyclist reaching down and adjusting thebuckle of the strap. In many situations, such as a sudden stop, thecyclist does not have sufficient time to loosen the strap, remove hisfoot and place it on the ground. Quite often, the result is that thecyclist falls since he cannot quickly disengage his foot from the strapand the pedal. If the cyclist happens to be using a cleat which fitsover the rear quill of the pedal, this further compounds the problemsince the rider must not only loosen the strap, but he must alsodisengage the cleat from the rear cage portion of the pedal.

Problems also exist when the cyclist attempts to insert his foot intothe above described pedal arrangements. The cage plates of the quillpedal typically rotate on an axle which is affixed to the crank arm of abicycle. This being the case, the natural resting position of the pedal,due to gravity, is approximately 180 degrees (upside down) from theposition in which the pedal is used when engaged with the cyclist'sfoot. This upside down position of the pedal, at rest, is due to theweighting of the pedal by the provided toe clips and straps. Thus, inorder to insert a shoe into the pedal arrangements, including toe strapsand clips, the rider must first manually rotate the pedal right side up,insert his foot into the pedal, and engage the cleat if one is beingused. He must then bend over and tighten the strap to obtain anefficient use of the pedal system.

Recent attempts have been made to alter the design of the conventionalpedal arrangement above described by making their shape more aerodynamicor lighter. However, for the most part, the dual arrangements haveretained a platform for the shoe to rest on, a toe clip, a strap, and arear cage for a cleat engagement. As a result, recent attempts have notsolved the above discussed problems.

One such attempt comprises a pedal system manufactured by Look. ThisLook system is shown on pages 129 and 145 of the 1987 Buyer's GuideEdition of the publication BICYCLING dated Mar., 1987 and published byRodale Press Inc. The Look system is also shown in U.S. Pat. No.4,686,867 to Bernard et al of 8-18-87. The Look system comprises asomewhat triangular shaped pedal body which revolves about a pedal axis.The top of the Look pedal is recessed at both its front and rearportions. There are protrusions at both the front and rear of the recessin order to hold a shoe cleat. The rear portion of the pedal, whichportion also comprises the rear part of the recess, is hinged andtensioned in order to allow this rear portion to rotate backwardly in anarcing manner in order to open it. A triangular cleat-like attachment isconnected to the cyclist's shoe and is designed to be inserted into therecess of the pedal body. The cyclist interlocks the shoe cleat with thepedal body by pushing a front portion of the cleat into the front recessof the body and by then pushing down with his heel. This pushing down ofthe heel opens a back cage comprising the rear recess and allows therear of the cleat to interlock with the rear recess. The cleat isdisengaged from the pedal body by a rotating or twisting motion ofcyclist's shoe.

Further attempts have been made to provide improved pedal arrangements.However, all of these attempts have not been successful in achieving theideal pedal system and they suffer from one or more of the abovediscussed problems. It can therefore be seen that the presentlyavailable bicycle pedal systems do not provide the performance of anideal pedal system.

SUMMARY OF THE INVENTION

The present invention solves the above discussed problems and achieves atechnical advance in the art by providing a bicycle pedal system havingthe characteristics of the idealized bicycle pedal system abovecharacterized. More specifically, the present invention comprises animproved bicycle pedal system that cooperates with a cyclist's shoewithout the use of toe clips or straps and, at the same time, providesperformance benefits not heretofore achievable. The pedal system of thepresent invention provides high pedaling efficiency for all forces thatmay be generated by a cyclist's foot. This includes downward forces,upward forces, as well as forward and backward forces. The pedal systemof the present invention further provides easy engagement of thecyclist's foot with the pedal. It further provides for easy removal ofthe cyclist's shoe from the pedal.

The present invention comprises two separate parts. The first partcomprises a cleat element which attaches to the ball area of a cyclist'sshoe. The second part comprises a pedal body that is attached to androtates about an axle connected to the bicycle's crank arm. The pedalbody is adapted to matingly engage with the cleat element on thecyclist's shoe. In a first embodiment of the present invention, thepedal body has of a forward extension of the top front portion of thepedal body. This extension is of the same longitudinal radius along itsleading edge as is the longitudinal radius of the rear surface of thepedal body. This extension has a vertical radius on its forwardextremity that is different from that of its longitudinal radius. Thefront portion of the shoe cleat is designed to accept the frontextension portion of the pedal body. This front portion of the shoecleat consists of a grooved inner channel having an inner longitudinalradius along its width and depth with this radius being the same as thelongitudinal radius of the front extension of the pedal body. Anadvantage provided by this embodiment of the invention is that inaddition to allowing the front extension of the pedal body to easilyengage the forward portion of the shoe cleat, it provides a solidnon-moving platform for the cyclist's foot to pull against. It alsoaffords a natural and easy path when the cleat is to be disengaged fromthe main pedal body.

The heel or rear portion of the pedal body has an enclosed depressibletensioned spring loaded detent mechanism which protrudes from a rearvertical surface of the pedal body. This detent mechanism is basicallytriangular in shape when viewed from the side. The rear vertical surfaceof the pedal body has a longitudinal radius along its width and trailingedge with this radius matching the rear longitudinal radius of a rearportion of the cyclist's shoe cleat. This depressible detent mechanismis designed to matingly engage with rear portion of the cleat, and inparticular, is designed to engage an inner shelf on the rear portion ofthe cyclist's shoe cleat.

The heel or rear portion of the cleat provides an advantage that is animportant part of the invention. This rear portion extends in a downwardmanner from the sole of the cyclist's shoe to a depth that is similar tothat of the pedal body. This rear portion of the cleat also contains aninner channel having a longitudinal radius that is of the same radius asthe longitudinal radius of the rear vertical surface of the pedal body.The channel has a seating cavity having a depth which is greater in itscenter and which decreases symmetrically as each side of the cleat isapproached. As a result of the design of this channel, the pedal systemprovided by the invention has the ability to re-center itself in itsoptimum position after encountering torsional shocks or other motionswhich do not exceed the predetermined level at which the pedal and cleatdisengage from one another.

During the use of the provided pedal arrangement, the rider simplyplaces the front of his shoe over the pedal body and engages the frontof the attached cleat with the front extension of the pedal body. Therider then applies a downward pressure with the rear of his foot. Thisallows the rear portion of the shoe cleat to depress the triangularshaped detent mechanism in the pedal body and to matingly engage therear part of the pedal body with the rear of the cleat. Once the pedalbody is engaged fully with the shoe cleat, a lower horizontal surface ofthe triangular detent mechanism is at rest against an inner shelf on thebottom rear area of the cleat. The detent mechanism cannot be compressedfrom this position by upward forces. It therefore becomes virtuallyimpossible to disengage the pedal from the cleat by using any type of apulling motion of the cyclist's foot. This is a most desirable feature.

To release the shoe from the pedal body, the rider simply twists hisfoot with sufficient force to exceed a predetermined level of force. Bytwisting his foot, the channel walls in the rear portion of the cleatengages and depresses the sides of the triangular shaped detentmechanism. When this force exceeds a predetermined amount, the detentmechanism is fully depressed and this allows the cleat to rotate awayfrom the pedal body. Should the lateral force be less than that requiredto release the shoe cleat the cleat automatically returns itself to itscenter position on the pedal body due to the longitudinal radius of thechannel contained in the rear portion of the cleat.

The pedal body of the invention has symmetrical longitudinal radii alongboth its front and rear extremities. The similar radii facilitate thedisengagement of the cleat from the pedal body when sufficient torsionalforces are generated. Under such conditions, the concave portion of therear portion of the cleat depresses the tensioned release detent. Thedetent mechanism depresses and allows the front and rear extensions ofthe cleat to rotate along the symmetrical longitudinal radii of thepedal body. When these lateral forces equal or exceed a predeterminedlevel, a rotation of the cyclist's shoe and cleat disengages the cleatfrom the pedal body. Should the lateral forces be removed before thepredetermined level of the force is generated, the front and rearportions of the cleat return rapidly to the longitudinal center of thepedal body so that the pedal body and the cleat remain engaged.

It may therefore be seen that the pedal system of the invention solvesthe problems of prior arrangements and provides an advance in the art.

OBJECT OF THE INVENTION

It is an object of this invention to provide an improved bicycle pedalsystem for affixing a cyclist's shoe to a bicycle pedal.

It is another object to provide a novel bicycle pedal system which isreleasable from a cyclist's shoe with the use of only a torsional motionof the cyclist's foot.

It is another object to provide a novel pedal system which has thecapability not only to absorb torsional motion caused by momentaryforces, but to return the shoe cleat to its optimum position after theabsorption of such forces.

It is another object to provide an improved bicycle pedal which utilizessymmetrical radii on its front and rear portions for matingly engaging asecond symmetrical radius along front rear portions of a cooperatingcleat attached to a cyclist's shoe.

BRIEF DESCRIPTION OF THE DRAWING

These and other objects and advantages of the invention may be betterunderstood from a reading of the following description thereof taken inconjunction with the drawing in which:

FIG. 1 is a first view of a bicycle utilizing one possible embodiment ofthe pedal system of the present invention;

FIG. 2 is a bottom isometric view of the pedal system;

FIG. 3 is a top view of the cyclist's shoe cleat;

FIG. 4 is a side view of the cyclist's shoe cleat;

FIG. 5 is a front end view of the cleat;

FIG. 6 is a rear end view of the cleat;

FIG. 7 is a bottom view of the cleat;

FIG. 8 discloses a segment of the front end of the cleat;

FIG. 9 discloses a segment of a rear section of the cleat;

FIG. 10 is a top view of the pedal body;

FIG. 11 is a side view of the pedal body;

FIG. 12 is a bottom view of the pedal body;

FIG. 13 is a front end view of the pedal body;

FIG. 14 is a rear end view of the pedal body;

FIG. 15 is an exploded isometric view of the parts comprising the pedalbody;

FIG. 16 shows how the cleat is attached to a cyclist's shoe;

FIG. 17 is a side view showing the state of the shoe cleat and the pedalbody as the cyclist begins to engage the cleat with the pedal body;

FIG. 18 is a side view showing the cleat and the pedal body fullyengaged;

FIG. 19 is a bottom view showing the state of the shoe cleat and thepedal body as the cyclist twists his shoe to disengage his foot from thebicycle pedal;

FIG. 20 is an inner end view of the rear cleat segment of FIG. 9;

FIG. 21 is a cross sectional view taken along lines 21--21 of FIG. 20;and

FIGS. 22 and 23 together disclose details of an alternative exemplaryembodiment of the present invention.

DETAILED DESCRIPTION

FIG. 1 shows one possible exemplary embodiment of the bicycle pedalsystem of the present invention as comprising a cleat 3 and a pedal body2. Cleat 3 is attached to a shoe 4 of a cyclist. Pedal body 2 isattached by a shaft 5 to a bicycle crank arm 1. With the cyclist's shoe4 being attached to cleat 3, and with cleat 3 being matingly engagedwith pedal body 2, the cyclist's foot may exert pedaling forces againstaxle 5 and crank 1 in a downward manner, in an upward manner, as well asin a forward and backwards manner.

FIG. 2 shows a bottom view of the cyclist's shoe 4 and the manner inwhich it cooperates with cleat 3, pedal body 2, and axle 5. The pedalbody 2 is retained on axle 5 by means of a suitable retaining mechanismsuch as a C-spring clip (not shown). The inner end of axle 5 is attachedto crank arm 1 by any suitable means such as, for example, by means ofmale threads on the inner end of axle 5 and cooperating mating femalethreads in a hole in an outer portion of crank arm 1.

FIG. 3 is a top view of the cleat 3. This is the portion of the cleatthat attaches to the cyclist's shoe. Cleat 3 contains slots 6, 7, and 8which are adapted to receive screws for attaching the cleat to a shoe.The manner in which this attachment is achieved is shown in FIG. 16.

FIG. 4 is a side view of the cleat of FIG. 3. The left side (the front)of the cleat of FIG. 4 comprises an inner channel 9 having a curvedvertical radius 10. The right (the rear) of the cleat on FIG. 4comprises a lip or inner shelf 13 which is shown in greater detail onFIG. 9.

FIG. 5 is a front end view of cleat 3 of FIG. 4. FIG. 6 is a rear endview of cleat 3 of FIG. 4. FIG. 7 is a view of the bottom of cleat 3.Shown on FIG. 7 are the slots 6, 7, and 8 which receive the screws thatare used to attach the cleat to a cyclist's shoe.

FIG. 8 is an isometric segmented view of the front of cleat 3. Shown infurther detail in FIG. 8 are the inner channel 9 having the verticalradius 10 and having an inner longitudinal radius 31. With theconfiguration shown in FIG. 8, it can be seen that portion 33 is thefront extremity of the cleat and that portion 32 is the bottom mostextremity of the cleat as shown on FIG. 4. It can also be seen that theoutside surface portion of the front of the cleat between segments 32and 33 is curved and extends downwardly on FIG. 4 from the element 33portion to the element 32 portion. In summary, the front of the cleatcontains an inner portion, as shown on FIGS. 8 and 4, having an innercurved channel 9 having a vertical radius 10 and a longitudinal radius31.

FIG. 9 is an isometric view of a segment of the rear end of the cleat 3.The rear segment of the cleat on FIG. 9 has an inner recess or channel12 having a bottom longitudinal radius 11. Segment 34 comprises the rearmost extremity of the cleat. Element 13 comprises the top portion of aridge or shelf whose lower portion on FIG. 4 comprises a portion ofchannel 12. The details of channel 12 and shelf 13 are better shown onFIGS. 20 and 21.

FIG. 20 discloses a front end view of channel 12 in the rear portion ofthe cleat segment of FIG. 9. FIG. 21 comprises a sectional side view ofchannel 12 taken along axis 21--21 of FIG. 20. Channel 12 may be bestappreciated from a study of FIGS. 9, 20, and 21 taken together. As maybe seen, the channel 12 has a seating cavity and is the deepest in themiddle of the cleat and becomes increasingly shallow as the side of thecleat is approached. Channel 12 receives a detent mechanism 18 on thepedal body 2 when the pedal body and the cleat are fully engaged. Atthis time, the detent mechanism is fully extended and coacts with thedeepest portion of channel 12 in the middle of the cleat. The detentmechanism becomes increasingly compressed inwardly against spring 23 asthe cleat rotates as shown in FIG. 19, due to the fact that the detentmechanism 18 encounters the increasingly shallow portions of channel 12as the rotation of the cleat with respect to the pedal body increases.The detent mechanism clears channel 12 when the cleat is rotated to thepoint where the detent mechanism 18 clears the side of the cleat andchannel 12. Element 18 is then no longer compressed by the walls ofchannel 12 and the rear portion of cleat 3.

The details of the pedal body are shown on FIGS. 10, 11, 12, 13, 14, and15.

FIG. 10 illustrates the top of the pedal body 2 which has a frontextension portion 14 having a longitudinal radius 15 and a void 17. Therear portion of the pedal body 2 includes a metal plate 24, screws 25,and a detent mechanism 18.

FIG. 11 is a side view of the pedal body 2 of FIG. 10. On the left sideof FIG. 11 it is shown that the forward extension portion 14 has avertical radius 16. On the right side of FIG. 11 is shown a springhousing portion 21 of pedal body 2. Also shown on the right side of FIG.11 is a sloping portion 19 and a bottom horizontal surface 20 of detentmechanism 18.

FIG. 12 is a bottom view of the pedal body. Shown on the left side ofFIG. 12 is the longitudinal radius 15 of forward extension 14. Shown onthe right side is the longitudinal radius 22 of the rear extremity ofpedal body 2. The radii 22 and 15 are equal in order to facilitate therelease of cleat 3 from pedal body 2 as the cyclist exerts a twistingtorque on the shoe to which the cleat is attached.

FIG. 13 is a front end view of the pedal body having segment 14 whichcomprises the forward most extension of pedal body 2. FIG. 14 is a rearend view of pedal body 2 with detent mechanism 18 being shown togetherwith its upper sloping surface 19 and its lower horizontal surface 20.

FIG. 15 illustrates further details of the pedal body including theelements within the spring housing 21. Specifically shown on FIG. 15 arethe void 17, the forward extension 14 of pedal body 2 together with itslongitudinal radius 15. On the rear portion of the pedal body is aspring 23 adapted to be contained within spring housing 21. Also shownis plate 24 for the top portion of the rear half of the pedal body 2.Plate 24 is affixed to the pedal body 2 by means of screws 25. The plate24 has a downward retainer lip or portion 29 which is adapted to bearagainst vertical face 30 of the detent mechanism 20 when spring 23 anddetent mechanism 18 are enclosed within the spring housing 21 and whenplate 24 is affixed to the pedal body. The portion of detent mechanism18 that is restrained and contained within the spring housing 21 is theportion of element 18 that is to the left of vertical face 30. At thistime, vertical face 30 bears against the vertical lip 29 of plate 24. Atsuch times, the only portion of detent mechanism 18 that protrudes outof the pedal body is that to the right of vertical face 30. This is theportion that comprises sloping face 19 and bottom surface 20.

It may be seen from a study of FIGS. 4 through 10, which illustratesdetails of the cleat, and from a study of FIGS. 10 through 15, whichillustrate details of pedal body 2, that a cyclist engages his shoecleat 3 with pedal body 2 by tilting his foot slightly downward so thatthe channel 9 in the front of cleat 3 engages the forward extension 14of pedal body 2. At this time, the forward extension 14 is withinchannel 9 of cleat 3. The vertical radius 16 of the front of pedal body2 is equal to the vertical radius 10 of channel 9. The horizontallongitudinal radius 15 of pedal body 2 is equal to the horizontallongitudinal radius 31 of channel 9. Thus the forward extension 14 ofthe pedal body at this time matingly engages with channel 9 on theforward portion of cleat 3. Having interlocked the front of cleat withthe front of the pedal body in this manner, the cyclist next moves hisheel down so that the ridge portion 13 of cleat bears against the slopedportion 19 of detent mechanism 18. This downward force causes detentmechanism 18 to compress inward until it is flush with the rear mostsurface 22 of the pedal body. The cyclist then continues to push theheel portion of his cleat down. When the heel portion is depressedsufficiently so that the horizontal bottom portion 20 of detentmechanism 18 clears the top portion of shelf or ridge 13, detentmechanism 18 then snaps to the right on FIG. 15 and enters the rearcleat channel 12 and its cavity of FIG. 9.

Once the detent mechanism snaps to the right as shown on FIG. 11 andenters the rear cleat channel 12 of FIG. 9, the cleat and the pedal bodyare firmly interlocked with each other. At this time, the cyclist mayexert forces in any direction to pedal the bicycle. These forces may bein a downward direction, in an upward direction, or forward orbackwards. Regardless of the direction of the force, the cleat and thepedal body remain interlocked and idealized pedaling efficiency isachieved in so far as concerns the interlocking relationship between thecleat attached to the cyclist's shoe and the pedal body.

The cyclist may controllably disengage his foot and cleat 3 from pedalbody 2 by exerting a twisting force on his shoe and cleat 3. At suchtimes, cleat 3 is free to rotate with respect to pedal body 2 since thelongitudinal radii 15 and 22 of the pedal body are equal to thelongitudinal radii 31 and 11 of the cleat. Since these four radii areequal, a twisting motion is easily achieved. The rear channel 12 and itscavity of the cleat is configured in such a manner that it is deeper inthe middle portion of the cleat and so that it becomes increasinglyshallow towards the side portions of the cleat. Thus, detent mechanism18 is fully extended prior to the initiation of a twisting motion by thecyclist on the cleat. As the twisting motion progresses, the cleatrotates and the further it rotates, the more detent mechanism 18encounters the increasingly shallower portions of channel 12. When thetwisting motion has progressed to the point that the detent mechanism 18encounters the portion of the channel near the side of the cleat, detentmechanism 18 is fully compressed and the cleat can then be freely turnedfurther so that the detent mechanism 18 snaps out and becomes fullyextended as it clears the side of cleat 3. Thus, it can be seen that thecyclist may controllably cause his foot and cleat 3 to release frompedal 2 at any time the cyclist desires to achieve this release.

The configuration of the inner portion of channel 12 and particularlythe middle portion of channel 12 as shown on FIG. 9 is such that, incooperation with the spring tension exerted on detent mechanism 18,cleat 3 and pedal body 2 do not disengage from one another unless acertain predetermined twisting force is exerted on cleat 3 and pedalbody 2. Forces less than this predetermined amount may be encounteredduring the use of the bicycle. These forces may rotate cleat 3 slightlywith respect to pedal body 2 and, in this event, the detent mechanism 18compresses slightly. However, when each such momentary forces ceases,the tension provided by spring 23 on detent mechanism 18 causes cleat 3to return to its center position and once again fully engage pedal body2. Thus, in summary, forces less than a predetermined magnitude do notcause the cleat and the pedal body to become disengaged. However, whenforces that equal or exceed the predetermined magnitude are encountered,the cleat rotates a sufficient amount so that detent 18 clears the sideof the cleat and permits the cleat to be fully disengaged from the pedalbody under total control of the cyclist.

FIG. 17 discloses the state of shoe cleat 3 and pedal body 2 when thecyclist begins to engage the front of cleat 3 with pedal body 2. Theprocess is initiated when the cyclist puts his foot on top of pedal body2 in such a manner that the forward extension 14 of the pedal body isinserted into channel 9 in the front of cleat 3. Having done this, thecyclist then pushes down on the heel portion of his foot so as to pushridge 13 of the cleat against the inclined surface 19 of the detentmechanism 18. The pressure exerted by ridge 13 on the inclined surface19 pushes detent mechanism 18 to the right on FIG. 17 and compressesspring 23 shown on FIG. 15. Element 18 moves further and further to theright as the pressure on surface 19 by ridge 13 increases.

As the pressure on detent mechanism 18 increases, it moves further andfurther to the right until its lower horizontal surface 20 clears theupper surface of ridge 13. At this time, detent mechanism 18 snaps tothe left and enters channel 12 and its cavity in the rear portion of thecleat as shown on FIG. 18. The pedal 2 and cleat 3 are fully engaged atthis time and the cyclist may exert pedaling force in any direction. Anupward pedal force is easily accommodated by the pedal system of thepresent invention since the lower surface 20 of detent mechanism 18bears against the bottom portion of channel 12 and against the upperportion of ridge 13. The rear portion of the cleat 3 cannot becomedisengaged from the pedal body 2 as upward force is generated sincedetent mechanism 18 cannot be compressed by such forces.

FIG. 19 shows the state of the pedal body 2 and cleat 3 after thecyclist rotates his foot to the point where detent mechanism 18 nolonger engages the channel 12 and the rear portion of cleat 3. Prior tothe initiation of this disengagement by the cyclist, the pedal body 2and shoe cleat 3 are fully engaged so that the longitudinal axis a--a ofthe shoe cleat coincides with the longitudinal axis b--b of pedal body2. At this time, the detent mechanism is fully extended within the rearcavity 12 of cleat 3. When the cyclist twists his foot to disengage itfrom pedal body 2, detent mechanism 18 is compressed as the shallowerwall portions of channel 12 are encountered. As priorly mentioned,channel 12 and its cavity are deepest at its center and is increasinglyshallow as the side of cleat 3 is approached. Thus, the further thecyclist twists his foot, the more detent mechanism 18 is depressed.Finally, as cleat 3 is rotated further, detent mechanism 18 approachesthe side of the cleat and is fully compressed so that the outer tip ofelement 18 is in the same vertical plane as the rear extremity 22 ofpedal body 2. When the cyclist twists his foot further, the detentmechanism 18 no longer bears against the surface of channel 12 andelement 18 therefore clears the cleat and springs to the left as shownon FIG. 19. At this time, the cyclist may disengage the shoe cleat fromthe pedal body 2.

Modifications may be made to the disclosed pedal system to achieveresults different from the above described operation. For example, onFIG. 11 the bottom surface of the detent mechanism 18 is shown to beflat and horizontal. With this design, the surface 20 bears against theinner portion of ridge 13 when pedal 2 and cleat 3 are fully engaged. Atsuch times, it is impossible to separate the cleat and the pedal body byan upward force generated by the heel of the cyclist. However, undercertain conditions it may be desired to have the cleat release from thepedal body when a certain predetermined vertical force is generated bycyclist. If this be the case, such results could be achieved merely byaltering the design of detent mechanism 18 so that bottom surface 20slopes upwardly instead of being horizontal. The degree of upward slopeof surface 20 determines the vertical force required to release thecleat from the pedal body as an upward force is generated by thecyclist.

FIGS. 22 and 23, taken together, disclose an alternative embodiment ofthe invention. Shown on FIG. 22 is a shoe cleat 40 and a pedal body 41.The cleat has a front portion 45 and a rear portion 46 containing aspring 47 within a chamber 149. Also contained within the forwardportion of chamber 149 is a ball 48 with the left end of spring 47bearing against the right side of ball 48. Ball 48 extends outward fromsurface 148 on the front extremity of rear portion 46 of the cleat.Surface 148, as shown on FIG. 22, is closely positioned with respect tosurface 69 on pedal body 41.

The pedal body 41 is mounted on shaft 42 and contains a channel orgroove 44 in its front portion. The front portion of the shoe cleat 40contains a rearwardly arcuate protruding ridge portion 43 which isadapted to coact with arcuate groove 44 in pedal body 41.

FIG. 23 is a bottom view of shoe cleat 40 which is attached by means ofscrews (not shown) to a cyclist's shoe in a manner similar to that ofFIG. 16. As can be seen from FIG. 23, cleat 40 has a toe portion 66having a transverse front extremity 45 and a rear facing arcuate ridge43. Reference number 57 designates the forward arcuate extremity ofpedal body 41. The rear facing extremity of rearwardly projecting ridge43 on the rear portion of toe portion 66 is shown by the arcuate dashedlines 55. This rear segment of the toe portion 66 is trapezoidal inconfiguration and is bounded by element 61 on its left side, element 59on its top, element 60 on its bottom and element 55 on its right.

The rear portion of the pedal body is generally designated as 68 and hasa rear extremity 69 which is transverse to the longitudinal axis of thepedal body. The sides of the pedal body in its rear portion aredesignated 70 and 71. The upper and lower rear portions of the pedalbody (on FIG. 23) are cut away so that the rear extremity 69 isconnected to side 71 by segment 63 and to side 70 by segment 64. The cutaway portions of the rear portion of the pedal body permit the cleat andthe pedal body to be disengaged more easily in response to a twisting ortorsional force on cleat 40. The longitudinal radii of the ridge 43 ofthe toe portion of the cleat 40 and channel 44 of the toe portion ofbody 41 also contribute to the ease of disengagement.

Shoe cleat 40 and pedal body 41 are matingly engaged with one anotherwhen the cyclist puts his shoe and attached shoe cleat 40 on top of thepedal body 41 and inserts ridge 43 in the front portion of shoe cleat 40into groove 44 in the front portion of pedal body 41. Having done this,the cyclist pushes down on the rear portion of the shoe cleat 40 so thatthe top rear portion 53 of pedal body 41 engages the bottom of ball 48.Increasing pressure by the cyclist's foot at this time forces ball 48 tothe right against spring 47. As ball 48 is further forced to the right,it enters the cavity 49 in the rear portion of pedal body 41. At thistime, ball 48 snaps to the left so that pedal body 41 and shoe cleat 40are fully engaged. The cyclist may generate pedaling forces in anydirection at this time.

The shoe cleat 40 and pedal body 41 are disengaged from one another whenthe cyclist rotates his shoe and the attached shoe cleat with sufficientpressure to compress spring 47 and move ball 48 to the right asufficient amount so that the cavity 49 and the rear portion of thepedal body 41 become disengaged from ball 48. The radii of the front ofthe cleat and the front of the pedal body permit these two elements todisengage. The design of cavity 48, ball 65, the arcuate groove 44 andprotrusion 43 permits the body and the cleat to rotate slightly, but yetnot disengage, in response to torsional forces and shocks less than thatrequired to effect a disengagement. The cleat and the body return totheir normal aligned position when these lesser forces cease.

Thus, in summary it can be seen that the pedal system of the inventionpermits the cyclist to achieve ideal pedaling efficiency with respect toall directions and force that the cyclist may generate. It may befurther seen that the pedal system of the present invention permits theshoe cleat to be easily interlocked with the pedal body without theburden of adjusting straps and the like. It may be further seen that thepedal system of the present invention permits the cyclist tocontrollably release his foot from the pedal at any time without theburden of readjusting or releasing straps and the like.

While the preferred embodiment has been set forth with a degree ofparticularity, it is to be understood that changes and modificationscould be made to the construction thereof which would still fall withinthe teachings of the claimed invention as set forth in the followingclaims.

I claim:
 1. A bicycle pedal system comprising:a shoe cleat adapted to beaffixed to a shoe of a cyclist, a pedal body adapted to be connected toa shaft on a bicycle crank arm, an arcuate transverse channel having afirst longitudinal radius on a front facing vertical surface of a frontextremity of said pedal body, and an arcuate protrusion on a rear facingvertical surface on a front portion of said cleat with said protrusionhaving a longitudinal radius equal to said radius of said body, saidprotrusion of said cleat being adapted to matingly engage in saidchannel of said pedal body, a spring loaded detent in a heel portion ofsaid cleat positioned in a horizontal plane below a horizontal planecomprising a top surface of said cleat, a seating cavity in a rearfacing vertical surface of a heel portion of said body and adapted toreceive said detent, means including said detent and said cavity formatingly engaging said pedal body and said cleat in an interlockedmanner with a downward motion of said heel portion of said cleat withrespect to said heel portion of said pedal body whereby pedaling forcesmay be applied to said pedal body by said cleat in an upward, downward,forward and backward direction with respect to the longitudinal axis ofsaid bicycle while minimizing motion of said cleat with respect to saidpedal body, and means including said detent and a front portion of saidbody and a front portion of said cleat for controllably disengaging saidcleat from said pedal body in response to a torsional force on said shoeto which said cleat is affixed with said force being less than saidupward pedaling force.
 2. The system of claim 1 wherein:said detentcomprises a spring loaded ball positioned in a front facing verticalsurface of said heel portion of said cleat, said ball is adapted to beforced against said heel portion of said body as said heel portion ofsaid cleat is first pressed downward against said heel portion of saidbody, and said ball is adapted to release outwardly from said heelportion of said cleat and enter said cavity in said body as said heelportion of said cleat is further pressed downward with respect to saidheel portion of said body, said rear facing vertical surface of saidheel portion of said body and said front facing vertical surface of saidcleat being adapted to butt against each other during relative movementbetween said cleat and said body when said cleat and said pedal body arematingly engaged to minimize motion therebetween.
 3. A bicycle pedalsystem comprising:a shoe cleat adapted to be affixed to a shoe of acyclist, a front and a rear downwardly extending projection of saidcleat, a pedal body adapted to be connected to a shaft on a bicyclecrank arm, an arcuate channel on a front facing vertical surface of afront extremity of said pedal body, an inner rear facing verticalsurface having an arcuate protrusion on said front projection of saidcleat, said arcuate channel in said body being adapted to receive and bematingly engaged with said arcuate protrusion of said cleat, a rearfacing vertical surface having a seating cavity on a rear extremity ofsaid pedal body, a spring loaded detent projecting outwardly from afront facing vertical surface of said rear downward projection of saidcleat, said detent being positioned in a horizontal plane below thehorizontal plane of a top surface of said pedal body, means includingsaid detent responsive solely to a downward movement of said rearprojection of said cleat for matingly engaging said cavity in said rearextremity of said pedal body with said detent in said rear projection ofsaid cleat in an interlocked manner whereby pedaling forces may beapplied to said pedal body by said cleat in an upward, downward, forwardand backward direction with respect to the longitudinal axis of saidbicycle, said rear facing vertical surface of said heel portion of saidcleat and said front facing vertical surface of said cleat being closelypositioned with respect to each other when said cleat and said pedalbody are matingly engaged to inhibit motion therebetween, and meansincluding said detent and said arcuate channel and said arcuateprotrusion for controllably disengaging said cleat and said pedal bodyin response to a torsional force on said cleat in excess of apredetermined amount that is unrelated to the pedaling force that can beaccommodated by said cleat and said body.
 4. The pedal system of claim 3wherein:a torsional force on said cleat less than said predeterminedamount rotates said cleat from its normal interlocked position an amountless than that required to disengage said cleat from said body, and saidcleat rotates and returns to a normal interlocked position collinearwith said pedal body upon a termination of said torsional force lessthan said predetermined amount.
 5. A bicycle pedal system comprising:ashoe cleat adapted to be affixed to a shoe of a cyclist, a pedal bodyadapted to be connected to a shaft on a bicycle crank arm, asubstantially flat horizontally oriented top portion of said cleat, anarcuate rear facing vertical surface on a downwardly extending frontprojection of said cleat affixed to said top portion of said cleat, avertical surface on an arcuate front extremity of said pedal body, anarcuate channel in said vertical surface on said front extremity of saidpedal body, an arcuate protrusion on said arcuate rear facing verticalsurface of said front projection of said cleat with said channel of saidbody being adapted to matingly engage and receive said arcuateprotrusion of said cleat, means including a downwardly extending rearprojection of a heel portion of said cleat and a heel portion of saidpedal body engaged with said heel portion of said cleat as well as saidarcuate rear facing protrusion of said cleat and said arcuate channel ofsaid body and a spring loaded detent extending horizontally outward froma front facing vertical surface of said heel portion of said cleat formatingly engaging said pedal body and said cleat in an interlockedmanner whereby pedaling forces may be applied to said pedal body by saidcleat in an upward, downward, forward and backward direction withrespect to the longitudinal axis of said bicycle while minimizingmovement of said cleat with respect to said pedal body, and meansincluding said detent and said arcuate channel in said body and saidarcuate protrusion of said cleat for controllably disengaging said cleatfrom said pedal body in response to a torsional force in excess of apredetermined amount that is independent of the pedaling force that canbe accommodated by said cleat and said body.
 6. The pedal system ofclaim 5 wherein:a torsional force on said cleat less than saidpredetermined amount rotates said cleat from its normal interlockedposition an amount less than that required to disengage said cleat fromsaid body, and said cleat rotates and returns to its normal interlockedposition collinear with said pedal body upon a termination of saidtorsional forces less than said predetermined amount.
 7. The system ofclaim 6 wherein said engaging means comprises:said downwardly extendingrear projection of said heel portion of said cleat affixed to said topportion of said cleat, a seating cavity in said rear facing verticalsurface of said heel portion of said body, said spring loaded detentprotruding horizontally outwardly from said front facing verticalsurface of said heel portion of said cleat, means on said heel portionof said body for compressing said detent element inwardly in response toa downward pressure exerted on said detent subsequent to the matingengagement of said arcuate channel in said body with said arcuateprotrusion of said cleat, said detent being effective to release andprotrude outwardly from said front facing vertical surface of said heelportion of cleat and to enter said seating cavity of said body as saidheel portion of said cleat travels downwardly so that said detent nolonger bears against an upper portion of said rear facing verticalsurface of said heel portion of said body, said rear facing verticalsurface of said heel portion of said cleat and said front facingvertical surface of said cleat being closely positioned with respect toeach other when said cleat and said pedal body are matingly engaged tominimize motion therebetween.
 8. The system of claim 7 wherein saidmeans for controllably disengaging comprises:a first longitudinal radiuson said arcuate front facing vertical surface on said front extremity ofsaid body, and a longitudinal radius equal to said first radius on saidarcuate protrusion on said arcuate rear facing vertical surface of saidcleat.
 9. A bicycle pedal system comprising:a cleat adapted to beaffixed to a shoe of a cyclist, a pedal body adapted to be connected toa shaft on a bicycle crank arm, a first longitudinal radius on a frontfacing vertical surface on a front extremity of said body, asubstantially flat horizontally oriented top portion of said cleat, afront downwardly extending projection on a front portion of said cleataffixed to said top portion, an arcuate rear facing vertical surfacehaving an arcuate protrusion on said front projection of said cleat, anarcuate channel in said front facing vertical surface of said frontextremity of said body with said channel having a longitudinal radiusequal to said first longitudinal radius of said body and to alongitudinal radius of said protrusion of said cleat, said channelfurther having a vertical radius, a downwardly extending rear projectionon a heel portion of said cleat affixed to said top portion of saidcleat and having an inner front facing vertical surface, a spring loadeddetent in said front facing vertical surface of said rear projection ofsaid cleat, a rear extremity of said body having an upper rear portion,a seating cavity in a rear facing vertical surface of said rearextremity of said body, said channel in said body being adapted toreceive and be matingly engaged with said protrusion in said cleat, saidspring loaded detent normally protruding outward from said front facingvertical surface of said rear projection of said cleat, means on saidupper rear portion of said body responsive to a downward movement ofsaid heel portion of said cleat for compressing said detent inwardlyafter said front extremity of said body is matingly engaged with saidcleat and as said rear extremity of said body presses against saiddetent, and said detent being adapted to release and extend outwardlyfrom said front facing vertical surface of said cleat and enter saidseating cavity of said body in response to a further downward movementof said rear projection of said cleat with respect to said rearextremity of said pedal body, said pedal body and said cleat beingmatingly engaged upon said release of said detent as it enters saidcavity, said cavity in said rear facing vertical surface of said bodyengaging said detent in said rear projection of said cleat when saidbody and said cleat are matingly engaged, said rear facing verticalsurface of said heel portion of said cleat and said front facingvertical surface of said cleat being closely positioned with respect toeach other when said cleat and said pedal body are matingly engaged tominimize motion therebetween, said radii being effective to effect adisengagement of said cleat and said body in response to a torsionalforce on said cleat in excess of a predetermined amount with saidtorsional force being independent of any pedaling forces that can beaccommodated by said interlocked cleat and said pedal body.
 10. A pedalsystem comprising:a solid pedal body for receiving a pedal axleextending perpendicular to and through said pedal body, a shoe cleat, afront downward extending projection on a front extremity of said cleat,an arcuate rear facing vertical surface having an arcuate protrusion onsaid front projection of said cleat, an arcuate forward facing verticalsurface having an arcuate recessed channel on a front extremity of saidbody, said channel being adapted to receive and be matingly engaged inan interlocked manner, a rear facing vertical surface on a rearextremity of said body, a seating cavity in said rear facing verticalsurface of said body, a rear downwardly extending projection on a rearportion of said cleat having a front facing vertical surface, a springloaded detent horizontally oriented perpendicular to said axle andextending outwardly from said front facing vertical surface of said rearportion of said cleat, and means including said detent responsive to adownward movement of said rear portion of said cleat for matinglyengaging said rear portion of said cleat and said rear extremity of saidbody by pressing an upper portion of said rear extremity of said bodyagainst said detent to depress said detent inwardly within said cleatuntil said detent clears said upper portion of said body and movesoutwardly into said cavity, said rear facing vertical surface of saidheel portion of said body and said front facing vertical surface of saidcleat being closely positioned with respect to each other when saidcleat and said pedal body are matingly engaged to minimize motiontherebetween, said arcuate vertical surface of said front extremity ofsaid cleat and said arcuate vertical surface of said front extremity ofsaid body having horizontal equal radii which allow said cleat to berotated horizontally to release said cleat and said body from each otherin response to a torsional force in a circular manner along the outsidedimensions of said pedal body when a predetermined torsional releaseforce is exceeded.